A Guide to the Night Sky: October 2016

A Guide to the Night SkyOctober 2016

By Tre Gibbs, LAAS

Everything is constantly in motion. For example, this past summer Jupiter, Mars and Saturn, like beacons in the night, ruled the evening skies.

Now that we are well into Autumn, it’s kind of fascinating to see just how much these steadily shining lights have wandered in such a relatively short span of time. Jupiter, which was high in the southwest just a few months ago, has wandered into our eastern pre-dawn skies, rising just before sunrise. Mars and Saturn are drifting further apart from each other, while Venus is slowly inching toward the quintessential ringed gas giant, low in our western sky just after sunset.

In fact by month’s end, Venus will have also slipped beyond Saturn in its continual orbit around our nearest star, The Sun, and Saturn, like Jupiter, will eventually also wander into our eastern, pre-dawn skies.

All of this motion may seem somewhat dizzying to some degree, but there is an amazing comfort and continuity to it all. For example, Earth’s own natural satellite, The Moon, orbits our planet every 27.3 days. Every culture on planet Earth has used the moon to measure time – our word month comes from moon. As the planets orbit the sun, we here on Earth see them slowly wander through our darkened skies – although if you know where to look, Venus is bright enough to be seen in daylight. In actuality, the planets are some of the brightest lights in the sky. Our ancestors noticed that these bright lights appeared to wander, while the stars appeared to remain “fixed”. The word planet or planeta is Greek/Latin for wander. There are five wandering lights or planets you can see with the naked eye: Mercury, Venus, Mars, Saturn and Jupiter. These appear to us on Earth as bright stars, but with one exception – they don’t twinkle like the stars do, rather they appear to be steady streams of light. There are also two other bright lights that wander through the sky; the Sun and the Moon. These seven lights that wander through the sky are the reason we have seven days of the week. If you know your Latin based languages, it’s pretty easy to figure out which planet is which day. Go ahead – try it…

On October 3rd just after sunset, low in the west, look for the young waxing crescent moon just above the brilliantly glowing Venus. On the evening of October 8th, the first quarter or half moon will travel the night sky just above the pinkish colored Mars. And on the morning of the 27th, the waning crescent moon, barely visible as a thin sliver, will hang just above mighty Jupiter, low in our eastern, pre-dawn skies.

The monthly lunar cycles, the orbiting planets, the changing seasons, – all of this constant motion is incredibly comforting in so many ways. So take the time to simply look up, contemplate and enjoy this incredible spectacle for yourselves.